Apparatus and method for installing roof moisture barrier fabric

ABSTRACT

A trolley carrying a roll of vapor retarder fabric is supporting on building roof purlins and moved along the purlins as the fabric is dispensed onto the purlins under longitudinal tension. Fabric tension is maintained to inhibit sagging thereof between the purlins by applying one braking force to the fabric roll and another braking force between the trolley and the purlins. The trolley has a rectangular support frame with opposite sides and front and rear ends. Rotatable rollers adjacent the rear end movably support the frame on the purlins, and a friction brake adjacent the front end engages the purlins. A handle attachment adjacent the rollers receives a handle for tilting the frame about the rollers to release the frame brake and push the trolley along the purlins. A frame guide roller extends downwardly from the front end of the frame for engaging a side of a purlin to prevent skewing of the frame relative to the purlins. Fabric roll supports extend upwardly from the frame sides between the front and rear frame ends for supporting a roll of vapor retarder fabric.

BACKGROUND OF THE INVENTION

[0001] This application relates to the art of buildings and, more particularly, to an apparatus and method for installing vapor retarder fabric on building roofs. The invention is particularly applicable for use in installing vapor retarder fabric on steel frame building roofs and will be described with particular reference thereto. However, it will be appreciated that the invention has broader aspects and can be used for laying down vapor retarder fabric in other environments.

[0002] Metal frame buildings typically have a plurality of spaced-apart roof purlins that are covered with a vapor retarder fabric, fiberglass insulation and roof panels. The vapor retarder fabric commonly is installed by placing a large roll of same on a carriage that is supported on the purlins. The carriage is moved along the purlins as the fabric is dispensed from the roll onto the purlins. The fabric must be supported to prevent it from sagging or falling between the purlins until the insulation and roof panels are installed over the fabric.

[0003] One arrangement for supporting the vapor retarder fabric between the purlins includes a flat support grid or plate on the carriage that extends between the purlins beneath the fabric as shown and described in U.S. Pat. Nos. 4,967,535 and 5,653,081. Beginning in line 31 of column 6, the '081 patent mentions the desirability of maintaining longitudinal tension in the fabric. However, high tension in the fabric tends to cause the carriage to move relative to the purlins and this relieves the tension. Beginning in line 17 of column 3, the '535 patent discloses hinged brake bars on the carriage for slidably engaging the purlins to inhibit movement of the carriage. This brake arrangement is inadequate as evidenced by the use of the support grid beneath the fabric.

[0004] In another arrangement, strips of double stick adhesive tape are applied between the purlins and the fabric as the fabric is dispensed from the carriage. This is rather cumbersome and expensive, and the tape does not stick well if the purlins are dirty or wet, or if the temperature is very low.

[0005] It would be desirable to have a more reliable way of maintaining tension in the vapor retarder fabric to prevent it from sagging or falling between the purlins.

SUMMARY OF THE INVENTION

[0006] Apparatus for installing vapor retarder fabric over building roof purlins comprises a trolley having support rollers for movably supporting the trolley on a pair of adjacent purlins. The trolley carries a roll of vapor retarder fabric that is dispensed and laid down on the purlins beneath the trolley rollers as the trolley is moved along the purlins.

[0007] In one arrangement, the trolley is a generally rectangular frame having opposite side frame members and front and rear frame members that extend between the side frame members. The rotatable support rollers are mounted on the frame adjacent the rear end thereof for engaging a pair of spaced-apart adjacent purlins.

[0008] Friction brake material is applied to the underside of the frame adjacent the front end thereof for engaging the upper surfaces of the purlins to inhibit movement of the trolley along the purlins unless the front end of the trolley is tilted upwardly. This braking action inhibits movement of the trolley along the purlins so that the vapor retarder fabric remains in tension to prevent same from sagging between adjacent purlins.

[0009] A handle attachment at the rear end of the frame receives an elongated handle for use in pushing the trolley along the purlins and for tilting the frame about the rollers to lift the trolley front end from engagement with the purlins.

[0010] Fabric roll supports extend upwardly from the opposite sides of the frame between the front and rear ends thereof for supporting a roll of vapor retarder fabric. A fabric guide member extends across the frame adjacent the support rollers for guiding the fabric from the roll between the support rollers and purlins.

[0011] The roll of vapor retarder fabric is positioned on the trolley closely adjacent the front end thereof so that maximum weight is applied for engaging the brake material with the purlins.

[0012] A vertical guide roller depends from the front end of the frame for engaging the side of one of the purlins to prevent skewing of the frame relative to the purlins as it is moved therealong.

[0013] A plurality of the trolleys are positionable in staggered relationship on a plurality of different adjacent purlins for applying the fabric to a plurality of adjacent purlins at the same time. Fiberglass insulation then is applied in a direction perpendicular to the purlins and roof panels are attached to the purlins over the insulation. Workers then may stand on the installed roof panels for moving the trolleys along the purlins.

[0014] It is a principal object of the present invention to provide an improved apparatus and method for installing vapor retarder fabric on roof purlins.

[0015] It is a further object of the invention to provide such an improved apparatus and method that maintains longitudinal tension in a vapor retarder fabric to prevent same from sagging between adjacent purlins.

[0016] It is another object of the invention to provide an improved trolley for use in applying vapor retarder fabric to roof purlins.

[0017] It is also an object of the invention to provide an improved method for installing vapor retarder fabric on building roof purlins.

[0018] It is an additional object of the invention to provide a trolley of the type described with a frame guide roller for preventing skewing of the trolley relative to roof purlins as the trolley is moved along the purlins.

[0019] It is a further object of the invention to provide such a trolley with an improved handle attachment for receiving a handle used to tilt and push the trolley along the purlins.

[0020] It is also an object of the invention to provide such a trolley with a brake to inhibit unintentional movement thereof along the purlins, and with a fabric guide member for guiding the fabric between the trolley rollers and the upper surfaces of the purlins.

BRIEF DESCRIPTION OF THE DRAWING

[0021]FIG. 1 is a diagrammatic perspective illustration of a metal frame building;

[0022]FIG. 2 is a cross-sectional elevational view of a portion of a building roof showing a vapor retarder, insulation and a roof panel applied to a roof purlin;

[0023]FIG. 3 is a top plan view of a trolley constructed in accordance with the present application;

[0024]FIG. 4 is a side elevational view of the trolley;

[0025]FIG. 5 is a cross-sectional view taken generally on line 5-5 of FIG. 4;

[0026]FIG. 6 is a top plan view of a fabric roll end support;

[0027]FIG. 7 is a front elevational view of the fabric roll end support;

[0028]FIG. 8 is a side elevational view similar to FIG. 4, and showing a roll of vapor retarder fabric supported on the trolley; and

[0029]FIG. 9 is a top plan view of a metal building roof framework having a plurality of trolleys in accordance with the present application supported thereon.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0030] Referring now to the drawing, wherein the showings are for purposes of illustrating certain preferred embodiments of the invention only and not for purposes of limiting same, FIG. 1 shows a very simplified schematic of a metal frame building having a plurality of spaced-apart parallel horizontal roof purlins 10-15 extending across opposite side walls 20, 22 intermediate opposite end walls 24, 26. Roof purlins 10-15 typically are horizontally positioned at gradually increasing elevations from one end wall 24 to the other end wall 26 so that the roof panels supported thereon slope downwardly in a direction from end wall 26 toward end wall 24.

[0031] The roof of metal frame buildings commonly has a vapor retarder fabric laid down across adjacent pairs of purlins 10-15. Insulation material then is laid down in a direction perpendicular to the purlins over the vapor retarder fabric. Finally, roof panels are laid down over the insulation perpendicular to the purlins and attached thereto in a known manner by the use of brackets and/or fasteners. FIG. 2 shows a typical arrangement with vapor retarder fabric 30, insulation 32, and roof panel 34 applied to purlin 11.

[0032] Referring now to FIGS. 3 and 4, a trolley A in accordance with the present application is in the form of a generally rectangular frame having parallel opposite side frame members 40, 42 and parallel front and rear frame members 44, 46 welded to the side frame members perpendicular thereto.

[0033] A cylindrical metal tube 48 is welded between side frame members 40, 42 adjacent rear frame member 46 and provides an axle for a pair of rotatable rollers 50, 52. The rollers are rotatably journaled on bearing assemblies that include inner bearing races having hubs 53-56 that are secured to axle 48 by set screws, only one of which is indicated at 57 on collar 53. The outer bearing races then rotate with rollers 50, 52 relative to axle 48 and the inner bearing races. Attaching the inner bearing races of the rollers to axle 48 by the set screws permits lateral adjustment of the rollers along rod 48 for properly locating same on a pair of adjacent purlins 11, 12.

[0034] Because the horizontal roof purlins are at different elevations, a trolley that is supported on two adjacent purlins is inclined from one side to the other. In the example shown in the drawing, purlin 11 is higher than purlin 10, purlin 12 is higher than purlin 1 1 and so on. Therefore, a trolley that is positioned on a pair of adjacent purlins adjacent side wall 22 for movement toward side wall 20 will be inclined downwardly in a direction from side frame member 42 toward side frame member 40.

[0035] A vertical guide roller B extends downwardly from the underside of front frame member 44 adjacent to but spaced inwardly from side frame member 40. Guide roller B engages the side of a purlin 11 to prevent skewing of the frame relative to purlins 11, 12 as trolley A moves therealong. Guide roller B includes a vertical metal tubular member 60 having a central elongated bolt 61 extending through a suitable hole in front frame member 44. A nut 63 is threaded onto bolt 61 for attaching guide roller B to front frame member 44. A plastic or metal sleeve member 62 is loosely received on tubular member 60 for rotation relative thereto. A cap member 64 received on the bottom end portion of tubular member 60 is attached thereto by set screw 65 for holding sleeve 62 rotatably on tubular member 60.

[0036] Additional vertical holes may be provided through front frame member 44 along the length thereof for receiving bolt 61 on guide roller B to adjust the position of the guide roller to the purlin spacing and to the direction of trolley inclination. For example, if the trolley is downwardly inclined in a direction from side frame member 40 to side frame member 42 with purlin 11 being higher than purlin 12, guide roller B would be placed closer to side frame member 42 to engage the inside surface of purlin 12.

[0037] Vertically upright roll support members 68, 70 are welded to opposite side frame members 40, 42 for supporting a roll of vapor retarder fabric thereon. Roll support members 68, 70 are located intermediate front and rear frame members 44, 46 and are much closer to front frame member 44 than to rear frame member 46 so that more of the weight of the fabric roll is applied to front frame member 44.

[0038] The axis of the roll of vapor retarder fabric preferably is spaced from the axis of rollers 50, 52 toward front frame member 44 a distance that is at least equal to or greater than two thirds of the distance from the axis of rollers 50, 52 to the longitudinal centerline of front frame member 44. However, it will be recognized that the spacing could be somewhat less than two thirds of this distance for some purposes, such as 10% less.

[0039] Thus, the roll support members are more adjacent the frame front end than the rear end thereof. With reference to FIG. 8, a roll C of vapor retarder fabric is wound on a mandrel 74 that is supported on roll supports 68, 70. The upper end of roll support 70 has a laterally opening socket member 76 welded thereto for receiving one end portion of mandrel 74. The opposite end portion of mandrel 74 is rotatably supported on roll support 68 by a brake member that will be described with reference to FIGS. 6 and 7.

[0040] The leading end portion 80 of the flexible fabric extends from roll C beneath a fabric guide roller D, and then between support rollers 50, 52 and the purlins on which they rest. Fabric guide roller D includes a metal tube 82 welded between side frame members 40, 42 and having a plastic or metal sleeve 84 rotatably received thereon. The fabric may be coiled clockwise or counterclockwise, and may exit the roll at the top or bottom thereof as long as the finished side of the fabric faces downwardly when it is placed on the purlins. The fabric roll is positioned low on the trolley to minimize wind action on the roll and the fabric.

[0041] A handle attachment is provided for attaching a handle to trolley A for tilting same about the axis of rollers 50, 52 and for pushing the trolley along the roof purlins. The handle attachment is inclined upwardly for receiving an elongated handle that is inclined upwardly and extends rearwardly from trolley A.

[0042] In one form of handle attachment, an inclined hole is formed through rear frame member 46 for receiving a pin 88 that is welded to rear frame member 46. An angle member 90 that provides a handle rest or support is welded to rear frame member 46 outwardly of pin 88. An elongated tubular handle 92 shown in FIG. 5 has an open end forming a socket in which pin 88 is received. Downward force on the handle against angle member 90 tilts trolley A about rollers 50, 52 to raise the front end of the frame from the purlins.

[0043] The ability to tilt the entire frame also allows the frame to be tilted sufficiently to locate guide roller B above the purlins to clear obstacles such as braces or bolts. The underside of front frame member 44 has strips of rubber or other friction brake material 102, 104 such as rubber or rubber-like tape attached thereto for engaging the upper surfaces of the purlins to inhibit movement of trolley A along the purlins unless the front end of the frame is tilted upwardly.

[0044]FIGS. 6 and 7 show a mandrel support bracket 110 having a hook 112 receivable within tubular roll support 68 as shown in FIG. 6. A pair of plastic clamping members 114, 116 are positioned between bracket 110 and a metal plate 118. Suitable holes through bracket 110 and clamping members 114, 116 receive bolts 120, 122 that are threaded into tapped holes in plate 118. Semi-circular recesses in clamping members 114, 116 cooperate to provide a generally circular hole 126 therethrough for receiving the opposite end portion of mandrel 74. Tightening or loosening bolts 120, 122 varies the force with which the periphery of hole 126 engages the mandrel to function as a brake that permits rotation of the mandrel and the fabric roll while preventing overrunning of fabric roll C as the fabric is dispensed therefrom.

[0045] The trolley of the present application normally is first positioned at the high end of the building roof so that the trolley is moving downhill as the vapor retarder fabric is dispensed. A temporary work platform or scaffold is assembled at one end of the building for workers to stand on. Trolleys having rolls of vapor retarder fabric thereon are lifted to the roof in any suitable manner and positioned on the purlins. By way of example, a plurality of the trolleys having fabric rolls supported thereon may be placed in a container and lifted to the roof by a crane.

[0046] With reference to FIG. 9, a plurality of the trolleys are shown in staggered relationship because they laterally overlap one another. Trolleys A1 and A3 would first be positioned on purlins 11-12 and 13-14, and moved therealong to the positions shown after securing the starting ends of the fabric to the roof supports such as by the use of tape strips 141, 142, 143 on fabric 80 associated with trolley A in FIG. 9. The starting ends of the fabric associated with all of the other trolleys are similarly secured to the roof supports.

[0047] Trolleys A, A2 and A4 then are positioned on purlins 10-11, 12-13 and 14-15, and moved therealong to the positions shown after securing the fabric ends to the roof supports. Insulation material then is laid down in a direction perpendicular to the purlins up to trolleys A, A2 and A4 over the area that already has been covered by the vapor retarder fabric dispensed from all of the trolleys. Roof panels then are positioned over the insulation extending in a direction perpendicular to the purlins and secured thereto. The installers then may stand on the roof panels for advancing all of the trolleys an additional distance along the purlins while depositing the vapor retarder material thereon until additional insulation and roof panels can be applied. This procedure is repeated until the entire roof is covered. The trolleys may be removed from the opposite end of the roof in any suitable manner, such as by the use of a crane.

[0048] The brake for the fabric roll combined with the brake on the underside of front frame member 44 makes it possible to maintain very high longitudinal tension in the fabric so that it extends relatively straight across adjacent purlins. The high frictional engagement between brake strips 102, 104 on the underside of front frame member 44 inhibits movement of a trolley along the purlins to prevent relaxation of the tension in the fabric.

[0049] The vapor retarder sheet material that is applied may take many forms. In a typical arrangement, the vapor retarder material is a lamination of kraft paper, foil, nylon string and polypropylene. This flexible vapor retarder material sheet material commonly is referred to as a permeance barrier. The dimensions and spacing of the purlins will vary significantly from one building to another, and trolleys may be fabricated for use with any purlin size and spacing. In a typical arrangement with which the trolley of the present application has been used, the upper surfaces of the purlins are three inches wide and the purlins are spaced on 5 foot centers. The trolleys may be advanced to provide a 6 foot length of vapor retarder material that is then covered with 6 inches of fiberglass insulation followed by installation of roofing panels.

[0050] Although the rollers may take many forms, they preferably are generally concave for improved tracking along the purlins. In the arrangement shown, the rollers have outer peripheral surfaces that slope inwardly toward the center of the rollers from the roller opposite ends as shown in FIG. 3. Although other types of rollers may be used, the rollers that are illustrated are conventional rollers commonly used on boat trailers.

[0051] Although the invention has been shown and described with reference to a preferred arrangement, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the claims. 

I claim:
 1. Apparatus for installing a vapor retarder fabric on a plurality of spaced-apart roof support members comprising: a support frame having front and rear ends, rotatable support rollers adjacent said frame rear end for supporting the frame on a pair of spaced-apart roof support members, said support frame including upright supports adjacent said frame front end for supporting a roll of vapor retarder fabric, a sheet material guide member for guiding the fabric from the roll onto the roof support members beneath the support rollers as the support frame is moved along the roof support members, a roll brake for inhibiting rotation of the fabric roll, and a frame brake adjacent said frame front end that engages the roof support members to inhibit movement of the frame therealong, the frame being tiltable about the support rollers to raise the frame front end and disengage the frame brake from the roof support members.
 2. The apparatus of claim 1 including a support frame guide member depending from said support frame for engaging the side of a roof support member on which said support frame is positioned to inhibit skewing of the frame relative to the roof support members.
 3. The apparatus of claim 2 wherein said support frame guide member is rotatable about an axis extending perpendicular to said frame.
 4. The apparatus of claim 1 wherein said sheet material guide member is rotatable.
 5. The apparatus of claim 4 wherein said sheet material guide member is positioned adjacent said support rollers and is located between said support rollers and said upright roll supports.
 6. The apparatus of claim 1 including a handle attachment on said support frame for supporting a handle used to manually push said support frame along the roof support members.
 7. The apparatus of claim 6 wherein said handle attachment is located between said support rollers.
 8. The apparatus of claim 7 wherein said handle attachment includes an upwardly inclined pin and a handle support below said pin, the pin being receivable in an open end of a handle that is positionable against the handle support.
 9. The apparatus of claim 1 wherein said frame brake is a friction brake material.
 10. The apparatus of claim 9 wherein said frame includes a front frame member having an underside and said frame brake comprises a friction brake material attached to said underside of said front frame member.
 11. Apparatus for carrying and dispensing a vapor retarder sheet material from a roll of same comprising: a generally rectangular support frame having opposite side support frame members and front and rear support frame members extending between said side support frame members, a pair of spaced-apart rotatable support rollers carried by said support frame between said side support frame members adjacent said rear support frame member, upright roll support members extending upwardly from said side support frame members adjacent said front frame member for rotatably supporting a roll of vapor retarder sheet material on said support frame and dispensing same beneath said support rollers, and a friction brake material on said front frame member for engaging support surfaces on which said frame is supported.
 12. The apparatus of claim 11 including a handle attachment on said support frame adjacent to and between said support rollers.
 13. The apparatus of claim 12 wherein said handle support is inclined upwardly for supporting a handle extending upwardly and rearwardly from said support frame for tilting said support frame about said support rollers and for pushing said support frame to move same along while supported by said support rollers.
 14. The apparatus of claim 13 wherein said handle attachment is secured to said rear support frame member.
 15. The apparatus of claim 14 wherein said support rollers are rotatable about a roller axis, said rear support frame member being secured to said side frame members above said roller axis, and said handle attachment being secured to said rear support frame member above said roller axis so that a handle supported by said handle attachment extends across said roller axis above same.
 16. The apparatus of claim 15 wherein said handle attachment includes an upwardly inclined pin welded to said rear support frame member and a handle support welded to said rear support frame member outwardly of and below said pin so that a handle having a handle end socket is positionable with the handle socket receiving said pin while the handle end portion engages said handle support.
 17. The apparatus of claim 11 wherein said support rollers are positioned on the opposite side of said rear support frame member from said front support frame member.
 18. The apparatus of claim 17 including a vapor retarder sheet material guide member extending between said side support frame members adjacent said support rollers, said guide member being spaced from said support rollers in a direction toward said front support frame member.
 19. The apparatus of claim 18 wherein said sheet material guide member is rotatable.
 20. The apparatus of claim 11 wherein each said support roller has opposite roller ends and an outer peripheral surface that slopes inwardly toward the roller center from said opposite roller ends.
 21. The apparatus of claim 11 including a frame guide member depending from said front support frame member for laterally engaging a roof support member on which said support rollers are positioned.
 22. The apparatus of claim 21 wherein said frame guide member is rotatable about axis extending perpendicular to said frame.
 23. The apparatus of claim 11 wherein said front frame member has an underside and said friction brake material is on said underside of said front frame member for engaging roof support members on which said support rollers are positioned, said support frame being tiltable about said support rollers to move said friction brake material upwardly out of engagement with the roof support members.
 24. Apparatus for installing a vapor retarder sheet material onto parallel spaced-apart roof support members comprising: a generally rectangular support frame having opposite sides and front and rear ends, a pair of spaced-apart rotatable support rollers between said opposite sides adjacent said rear end, upright supports extending upwardly from said sides adjacent said front end for supporting a roll of vapor retarder material thereon, a transverse sheet material guide member extending between said opposite sides adjacent said support rollers and spaced from said support rollers in a direction toward said front end for guiding a vapor retarder sheet material beneath said support rollers, a vertical frame guide member depending from said support frame adjacent said front end for laterally engaging a roof support member on which said support rollers are positioned to inhibit skewing of the support frame, a frame friction brake adjacent said frame front end that engages roof support members on which the frame is supported to inhibit movement of the frame along the roof support members, and a handle attachment adjacent said rear end for attaching a handle used to tilt the front end of the support frame upwardly about the support rollers to release the frame friction brake and push the frame along roof support members.
 25. Apparatus for carrying and dispensing a vapor retarder sheet material from a roll of same comprising: a generally rectangular support frame having opposite side frame members and front and rear frame members extending between said side frame members, a pair of spaced-apart rotatable support rollers mounted between said side frame members on the opposite side of said rear frame member from said front frame member, a sheet material guide member extending between said side frame members adjacent said support rollers and below said rear frame member, upright roll supports extending upwardly from said side frame members adjacent said front frame member for supporting a roll of vapor retarder sheet material, a support frame guide roller depending from said front frame member adjacent one of said side frame members for laterally engaging a roof support member on which said support frame is positioned, a frame friction brake adjacent said front frame member that engages roof support members on which the frame is supported to inhibit movement of the frame along the roof support members, and a handle attachment on said rear frame member between said support rollers for receiving a handle used to tilt the support frame about the support rollers to release the frame friction brake and to push the support frame along roof support members.
 26. The apparatus of claim 25 wherein said front frame member has an underside, and said frame friction brake comprises a friction brake material attached to said underside for engaging roof support members on which said support frame is positioned.
 27. A method of installing vapor retarder fabric on a building roof having a plurality of spaced-apart parallel roof support members comprising the steps of: providing a trolley having front and rear ends and spaced rollers adjacent the rear end, the rollers being engageable with an adjacent pair of roof support members for supporting the trolley thereon, the trolley carrying a roll of vapor retarder fabric; positioning the trolley on a pair of adjacent roof support members with the rollers and the frame front end engaging the roof support members; positioning the vapor retarder fabric between the rollers and the roof support members; moving the trolley along the roof support members while applying longitudinal tension to the fabric and dispensing same onto the roof support members by tilting the trolley about the rollers to raise the trolley front end while pushing on the trolley; and maintaining longitudinal tension in the fabric by applying a braking force to the vapor retarder fabric roll and by applying a braking force between the frame front end and the roof support members.
 28. The method of claim 27 wherein the step of positioning the trolley on adjacent roof support members is carried out by positioning a plurality of trolleys on different ones of adjacent pairs of roof support members. 